The output shaft of a Downhole motor used within the oil industry for earth boring operations moves in an eccentric fashion. This accentric movement must be converted into a concentric movement for the drill bit to perform its intended function. At the present time this conversion is accomplished by means of a drive shaft having universal joint connections which connects the downhole motor to a bearing assembly rotating the drill bit.
The penetration of abrasive drilling fluids into the drive shaft universal joint assembly has an adverse effect on the operational life of the drive shafts. In order to prolong this operational life, attempts have been made to seal the universal joint assemblies. The universal joint assemblies of most drive shafts do not readily lend themselves to sealing. It has therefore come to be the practise to secure a lubricant filled rubber sleeve over the universal joint. This sleeve has a number of recognized disadvantages. It is common for it to slide out of position, where it can become damaged so it no longer serves its intended function, or can move into a position where it interferes with drilling operations.